OpenStack Neutron – building virtual routers

In a previous post, we have set up an environment with a flat network (connected to the outside world, in this case to our lab host). In a typical environment, such a network is combined with several internal virtual networks, connected by a router. Today, we will see how an OpenStack router can be used … Continue reading OpenStack Neutron – building virtual routers

OpenStack Neutron – architecture and overview

In this post, which is part of our series on OpenStack, we will start to investigate OpenStack Neutron - the OpenStack component which provides virtual networking services. Network types and some terms Before getting into the actual Neutron architecture, let us try to understand how Neutron provides virtual networking capabilities to compute instances. First, it … Continue reading OpenStack Neutron – architecture and overview

Virtual networking labs – building a virtual router with iptables and Linux namespaces

When you are trying to understand virtual networking, container networks, micro segmentation and all this, sooner or later the day will come where you will have to deal with iptables, the built-in Linux firewall mechanism. After evading the confrontation with the full complexity of this remarkable beast for many years, I have recently decided to … Continue reading Virtual networking labs – building a virtual router with iptables and Linux namespaces

Virtual networking labs – Open vSwitch in practice

In the last post, we have discussed the architecture of Open vSwitch and how it with a control plane to realize an SDN. Today, we will make this a bit more tangible by running two hands-on labs with OVS. The labs in this post are modelled after some of the How-to documents that are part … Continue reading Virtual networking labs – Open vSwitch in practice

Virtual networking labs – a short introduction to Open vSwitch

In the previous posts, we have used standard Linux tools to establish and configure our network interfaces. This is nice, but becomes very difficult to manage if you need to run environments with hundreds or even thousands of machines. Open vSwitch (OVS) is an Open source software switch which can be integrated with SDN control … Continue reading Virtual networking labs – a short introduction to Open vSwitch

Virtual networking labs – overlay networks

In the last post, we have looked at virtual networking on the Ethernet level. In modern cloud environments, a second class of virtual networks has gained importance, which uses higher level protocols to tunnel Ethernet frames. These networks are called overlay networks, and we will start to look at them in this post. VXLAN - … Continue reading Virtual networking labs – overlay networks